1. Field of Invention
The present invention relates to methods, systems, apparatus and products relating to calculation and execution of pin height adjustments within a bed of nails shape measurement gauge with respect to a measured subject substrate, such as glass substrates, and in particular, to using a bed of nails gauge for systematic shape measurement of glass substrates, such as liquid crystal display (LCD) glass sheets.
2. Description of Related Art
Producing flat product glass for displays, such as LCDs, involves many challenges. A key requirement in this process is the ability to minimize product distortion due to internal stresses in large product glass plates. Typical large product glass plates range in size up to 3.3 meters square.
Product distortion may be measured, for instance, using optical methods and gauging techniques, which have been developed over the past several years to enable distortion measurement via optical means. Distortion measurement may be done by comparing scribed reference marks on the product glass with scribed reference marks on a precision scribed glass master, before and after the glass shearing process. A measured difference between such scribe marks is relatable to a level of stress in the product glass.
As product glass sizes increase, measurement and control of the residual stress and shape deformation become more difficult. Nevertheless, larger glass product sizes are desired, and thus it is necessary to develop new products and methods that achieve larger-size product glass having residual stress and shape deformation within acceptable ranges.